Regression, lots of error/warning messages when closing QML viewer

This was seen with QML compiled from qt/qt-qml and HEAD at
9ae50ce40c1bc571c867bc698f2c53839c2c6932

Closing the QML viewer (e.g. after running tesla) now give this error output:

QDeclarativeContext: Cannot set property on invalid context.
QDeclarativeContext: Cannot set context object on invalid context.
QDeclarativeComponent::beginCreate(): Cannot create a component in an invalid context
()
QML Component (unknown location) Delegate component must be Item type.
/home/mathias/gitorious_qt-qml/bin/qml exited with code 0